This invention relates to wheel adjustment/alignment apparatus and methods for vehicles, and, more particularly, relates to apparatus and methods for adjusting the control arm/wheel spindle relationship at an upper or lower ball joint connection to produce changes in the camber, caster or camber/caster combination angle of a vehicle wheel.
Most vehicles consist of a tire/wheel mounted to a spindle which is attached to the vehicle through upper and lower control arms with the main connection being through ball joints mounted to the control arms. Some vehicles, however, are manufactured without provision for adjusting camber angle in the wheels. For example, some vehicles utilize an xe2x80x98Axe2x80x99 shaped upper control arm with xe2x80x98silent-blocxe2x80x99 type pivot isolators pressed into the inner pivot locations of the arm. The inner control arm in some such cases has a xe2x80x98uxe2x80x99 shaped bracket welded into it, with cross-holes in the inner bracket and inner control arm for locating the mounting bolts that engage and clamp the xe2x80x98silent-blocxe2x80x99 pivot isolators. This arrangement locates the inner pivots of the upper control arm in a fixed position with no means of adjustment.
The camber and caster angles of the tire/wheel (relative to the vehicle frame) directly effect vehicle handling and tire wear and is therefore of great importance. Camber angle is typically specified by the factory at a specific vehicle ride height (the distance from the ground to some point in the vehicle suspension corresponding to the vehicle frame center of gravity). The camber angle established between the plane of the tire and wheel and the vertical plane through the vehicle frame is directly impacted by any changes in the suspension components. Such changes can occur through damage to the components or through modification, intentional or unintentional, to the vehicle ride height. Thus, vehicles with raised or lowered ride height or damaged suspension links will typically not maintain proper camber angle and require means for readjusting the camber angle to the original specifications if handling and tire longevity are not to be sacrificed. Moreover, it may become desirable to correct a mis-aligned vehicle with other than strictly camber corrections.
One current means for adjusting camber angle consists of changing the relative position of the control arm to the vehicle at the body mounting points. This allows the control arm, and thus the ball joint position, to be moved laterally with respect to the vehicle, thereby changing the camber angle of the spindle and the tire/wheel. This method will not work if the vehicle""s control arm mounting scheme prevents replacing the fixed control arm body mounts with an adjustable mounting apparatus.
Another current means for adjusting camber angle provides for replacement of the upper or lower ball joint with an offset ball joint that, when rotated, allows changes of the position of the spindle mounting point around an offset arc. While this enables the camber angle to be modified, it at the same time modifies the caster angle, sometimes undesirably, due to its fixed radial offset arc. Further improvements could thus be utilized
This invention provides apparatus and method for selective positioning of a vehicle ball joint relative to a control arm to provide adjustability of wheel camber, wheel caster, and/or a combination of wheel camber and caster. The apparatus is simple to install and adjust, requires no modification of other suspension components, and provides for adjustment of wheel camber independent of caster adjustment.
The apparatus includes a mount configured to be secured at an end of the ball joint, the mount having a stud extending from a slide. A guide is securable at the control arm and receives and rotationally stabilizes the slide of the mount. The guide has a slot for receiving the stud of the mount therethrough, the stud and the slide thus movable linearly at the guide.
An insert is installed through an opening in the control arm with a rim thereof extendible through the control arm opening and receivable adjacent to the guide. A slot in the insert is substantially coextensive with the slot of the guide, the stud extending therethrough. A fastener is engageable with the stud to secure the selected position of the ball joint by securing the position of the stud relative to the slots in the insert and the guide. The ball joint may be pre-installed in the apparatus of this invention (and thus a part thereof), or provided separately from the apparatus of this invention for installation by service personnel.
The method of this invention provides for adjusting the relative position of a vehicle ball joint and a central axis of the control arm opening. The method includes the steps of affixing a stud to the ball joint and positioning the stud through the control arm opening. Linear movement of the stud perpendicular to the axis of the control arm opening is guided while rotational movement of the stud in the opening is stabilized. When desired adjustment is achieved, the stud is secured at the selected position relative to the axis of the control arm opening.
It is therefore an object of this invention to provide apparatus and methods for selective positioning of a vehicle ball joint relative to a control arm to provide adjustability of wheel camber, wheel caster, and/or a combination of wheel camber and caster.
It is another object of this invention to provide an apparatus for selective vehicle wheel angle positioning that is simple to install and adjust on a vehicle, requires no modification of other suspension components, and provides for adjustment of wheel camber independent of caster adjustment.
It is still another object of this invention to provide an apparatus for selective positioning of a vehicle ball joint securable between a control arm and a wheel mounting, the apparatus including a mount configured to be secured at an end of the ball joint and including a stud extending from a slide, and a guide securable at the control arm and receiving and rotationally stabilizing the slide of the mount thereat, the guide having a slot for receiving the stud of the mount therethrough, the stud and the slide movable linearly at the guide.
It is yet another object of this invention to provide an apparatus mountable at a vehicle control arm opening and at a spindle to provide selectable camber correction of a vehicle wheel including an insert having a rim and a slot, the rim extendible through the control arm opening, a guide receivable adjacent to the rim of the insert and including a slot substantially coextensive with the slot of the insert, a slide with a stud extending from one side thereof and receivable at the guide with the stud receivable through the slots of the guide and the insert, a ball joint affixable at one end to the spindle and at another end to the slide, and a fastener engageable with the stud.
It is yet another object of this invention to provide a method for adjusting relative position of a vehicle ball joint and a central axis of a control arm opening including the steps of affixing a stud to the ball joint, positioning the stud through the control arm opening, guiding linear movement of the stud perpendicular to the axis of the control arm opening while rotationally stabilizing the stud in the opening, and securing the stud at a selected position relative to the axis of the control arm opening.
With these and other objects in view, which will become apparent to one skilled in the art as the description proceeds, this invention resides in the novel construction, combination, arrangement of parts and method substantially as hereinafter described, and more particularly defined by the appended claims, it being understood that changes in the precise embodiment of the herein disclosed invention are meant to be included as come within the scope of the claims.
The accompanying drawings illustrate a complete embodiment of the invention according to the best mode so far devised for the practical application of the principles thereof, and in which:
FIG. 1 illustrates a typical suspension system on a vehicle as supplied by a manufacturer;
FIG. 2 illustrates the suspension system of FIG. 1 with the apparatus of this invention installed;
FIG. 3 is a perspective view of the camber/caster adjusting apparatus of this invention;
FIG. 4 is a front elevation view of the apparatus of FIG. 3;
FIG. 5 is a side elevation view of the apparatus of FIG. 3;
FIG. 6 is a top elevation view of the apparatus of FIG. 3;
FIG. 7 is a sectional view taken along section line 7xe2x80x947 of FIG. 4; and
FIG. 8 is an exploded view of the camber/caster adjusting apparatus of this invention.